Drawing-pen.



G. SCHOENNER.

DRAWING PEN.

APPLICATION FILED Dec. 9. I912.

Patented June 22, 1915.

2 SHEETS-SHEET lwill)! THE NORRIS PETERS 60-. FHOTO-LITHOI. WASHINGTON.D. C.

G. SCHOENNER.

DRAWING PEN.

APPLICATION FILED 020.9. 1912.

Patented J une 22, 1915.

2 SHEETS-SHEET 2.

awr /41% a Q? a 0&-

f LZJr ey THE NORRIS PETERS 60.. PHOTO-LITHOV. WASHINGTON, D. C.

GEORG SGI-IOENNER, OLE NUREMBERG, GERMANY.

DRAWING-PEN.

intense.

Specification of Letters Patent.

Patented June 22, 1121-6.

Application filed December 9, 1912. Serial No. 735,614.

To all whom it may concern Be it known that I, Gnone ScHonNNnR, asubject of the German Emperor, residing at Nuremberg, Bavaria, Germany,have invented certain new and useful Improvements in Drawing-Fens, ofwhich the following is a specification.

My invention relates to improvements in mathematical drawinginstruments.

It refers particularly to that class of drawing-pens which, whentemporarily opened for cleaning, and closed again, will assume theoriginal distance between the pen blades, so that the draftsman isdirectly able to continue drawing lines of the same width as beforewithout readjustment of the pen.

The invention is illustrated in the accompanying drawings in which:

Figure 1 represents in side elevation a closed drawing-pen whichembodies in desirable form the present improvements. Fig. 2 is a similarelevation of an open drawingpen. Fig. 3 shows in plan view the innerside of a sliding bar. Fig. 4 shows in similar view the inner side ofthe nether blade. Fig. 5 is a cross section on the line EF of Fig. 1.Fig. 6 is a cross section on the line GH of Fig. 1. Fig. 7 is a faceview of a part of a modification of the drawing-pen. Fig. 8 is apartial. longitudinal section through a closed pen and Fig. 9 a similarpartial section through an opened pen of this modification; and Figs.10, 11, 12 are correspond ing views showing slight changes in themodified form of pen.

Similar characters denote like parts in all the figures.

In the drawing-pen illustrated the adjusting screw 2 carries the littlehand-wheel 3 and has a neck 14. The screw passes through an opening 19in the nether blade 7. At the lower rim of the neck 14 there is a flange15 which seats in a socket in the blade 1, see Figs. 1, 3 and 5. Thusthe screw 2 is permitted to turn, but not to move in axial direction.

At the end of the screw 2 there is a nut 16 having a neck 17 andunderneath an enlargement 18. The nether blade 7 has a slot 19 which issufficiently wide for the passage of the enlargement 18 of the nut 16and further a longitudinal perforation 20 through which passes freely aheaded screw 21. The head 22 of this screw is on the outside of theblade 7 and acts as a handle for the adjust ment of a sliding bar 23.The screw 21 is screwed into the sliding piece 23 which is on one of thefaces of the blade 7. At some distance from the screw 21 a short screw24 is inserted in the sliding-piece 23, said pin 24c extending into theslot 20, but not through the same. This pin which need not necessarilybe screw-threaded and may be re placed by any ordinary pin or detent,serves to secure the sliding piece against turning about the screw 21.At its other end the said sliding piece is shaped to form a claw 25shown in detail in Fig. 3. This claw frictionally fits on theneck-portion 17 of the nut 16.

In the modification shown in Figs. 7 to 9 the hand-wheel 3 is fastenedupon the adjusting screw 2 between the two blades of the drawing-pen.The adjusting screw 2 is adapted to slide in a slot 27 of the netherblade 7. The nut 16 screwed upon the screw 2 slides in the slot 28 ofthe blade 1. The said slot 28, the width of which corresponds with thediameter of the nut 16, has on one end a widened portion 29 permittingof the passage of the enlarged edge 30 of the nut 16.

I adjust this drawing-pen by turning the small wheel 3. This causes arotation of the screw 2 while the nut 16 is prevented from turning bythe clamping action between the same and the blade 1. To open thedrawing-pen I move the wheel 3, the screw 2 with its head 26 and the nut16 in the direction of the arrow in shown in Fig. 8 until the nut 16 hasarrived in the wide portion 29 of the slot 28 and its edge 30 passesthrough the said wide portion 29 (see Fig. 9). To close the pen I pressthe blades 1 and 7 together and move the intermediate parts inopposition to the direction required for opening the pen until the nut16 and blade 1 are again engaged. Neither during the opening nor theclosing of the pen is there any turning of the hand wheel or the screw 2relative to the nut 16, so that the width or thickness of the lineremains unchanged.

The difference between the modification shown in Figs. 10 to 12 and thatshown in Figs. 7 to 9 is merely that in the former the hand-wheel is notbetween the blades, but on the outside. The hand-wheel 3 is secured tothe end of the screw 2 on which there is further provided an enlargement31 in such a way that between the same and the hand-wheel 3 the screw isadapted to slide in the slot 27. The adjustment of the pen isaccomplished by turning the handwheel 3 and the screw 2. On moving theintermediate parts in the direction of the arrow 00 shown in Fig. 11 theblade 7 and the nut 16 become disengaged, because the enlarged edge 30passes through the wide portion 29 of the slot 28. Thus there is also,in this case, no change in the thickness of the line caused by anopening or closing of the drawing-pen.

As hereinbefore described the drawingpens forming the subject matter ofthe present invention are provided each with a set screw and aninteriorly threaded nut located at the end portion of the set screw,said adjusting screw and the nut being freely passable through thenether blade and the nut being adapted to be locked to the nether bladeof the drawing-pen and released therefrom, whereby the adjustment of thepen for drawing lines of a certain width is retained and remainsunchanged when the pen blades are locked again after the same wereopened say, for the purpose of cleaning by moving the locking means toinoperative position.

I claimas my invention:

, 1. A drawing-pen retaining its adjustment for width of line,comprising a pen blade, a headed set screw passing freely through saidblade, a threaded nut located at the end of the set screw, a second penblade, the set screw and the nut being wholly free of said secondbladeand means in the second blade for locking the nut thereto, said lockingmeans and the screw being rela tively movable to bring the nut into andout of locking engagement with the locking means.

2. A drawing-pen retaining its adjustment for a width of line whenclosed again after cleaning, comprising a pen blade, a headed set screwpassing freely through said blade, a threaded nut located at the lowerend of the set screw, and having an enlarged locking bottom portion, asecond pen blade, the set screw and the nut being wholly free of saidsecond blade and means in the second blade for locking the nut thereto,said locking means and the set screw being relatively movable to bringthe nut into and out of locking engagement with the locking means.

3. A mathematical drawing-pen retaining its adjustment for a width ofline when closed again after cleaning, comprising a pen blade, a headedset screw swiveled in said blade, a threaded nut at the lower end of theset screw having a neck and an enlarged looking bottom portion, a secondpen blade, the set screw and the nut being freely passable through saidsecond blade and locking means in the second blade, said locking meansbeing movable to inoperative position.

In testimony waeree't I aiiix my signature in presence of two witnesses.

GEORG SCI-l OENNER.

lVitnesses Oscar: Boon, LEONHARD Konnnnn.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

